This review article demonstrates and shows the embryo transfer process in ART treatment; It also compares different embryo transfer timing and days to evaluate the pregnancy and implantation rates with day three versus day five embryo and day five versus day six embryo transfer. The review was carried out to prove that day five embryo transfer has better clinical pregnancy outcomes than day 3; thus, the embryo would spend more time developing blastocytes. Furthermore, day five embryo transfer is also preferred over day six embryo transfer since it fits the implementation window and endometrium receptivity.